I can see how some may be confused by the sign saying “No trespassing,” which, in some areas, could denote private property. However, it’s not uncommon for communities with restricted access to have signs like these outside of their communal areas, to make it known to those that don’t live in the neighborhood that access is off-limits to them.
The tooltip for Appropriate does note that places that may restrict access to a subset of people, like those that live in this neighborhood, are allowed. This is also outlined in the PRP clarification section. Not all reviewers may look at these though, but they should to prevent issues like this.